package org.netty.rpc.registry;


import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import org.netty.rpc.protocol.InvokerProtocol;

import java.io.File;
import java.lang.reflect.Method;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;

public class RegistryHandler extends ChannelInboundHandlerAdapter {
    //保存所有可用的服务
    public static ConcurrentHashMap<String, Object> registryMap = new ConcurrentHashMap<String, Object>();

    //保存所有相关的服务类
    private List<String> classNames = new ArrayList<String>();

    public RegistryHandler(){
        scannerClass("org.netty.rpc.provider");
        doRegister();
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        InvokerProtocol request = (InvokerProtocol) msg;

        if (registryMap.containsKey(request.getClassName())){
            Object clazz = registryMap.get(request.getClassName());
            Method method = clazz.getClass()
                    .getMethod(request.getMethodName(),
                            request.getParamTypes());
            Object result = method.invoke(clazz,request.getParams());
            ctx.write(result);
            ctx.flush();
            ctx.close();
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
    }

    private void scannerClass(String packageName){
        URL url = this.getClass().getClassLoader().getResource(packageName.replaceAll("\\.","/"));
        assert url != null;
        File dir = new File(url.getFile());
        for (File file : dir.listFiles()){
            //如果是一个文件夹继续递归
            if (file.isDirectory()){
                scannerClass(packageName+"."+file.getName());
            }else{
                classNames.add(packageName+"."+file.getName().replace(".class","").trim());
            }
        }

    }

    private void doRegister(){
        if (classNames.size() == 0){
            return;
        }
        for(String className : classNames){
            try {
                Class<?> clazz = Class.forName(className);
                Class<?> i = clazz.getInterfaces()[0];
                registryMap.put(i.getName(),clazz.newInstance());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }
}
